1. Field of the Invention
The present invention relates generally to molding systems, including devices, apparatus and methods for producing molded optical elements such as lenses. More particularly, the present invention relates to an injection molding apparatus for forming optically transmissive products with micro-refractive and/or diffractive surfaces.
2. Discussion of the Related Art
It is has been suggested to form a mold apparatus by etching diffractive patterns in a flat substrate, cutting the patterns from the substrate, and applying them to mold pins. The pins are used in mold cavities to form molded products with the desired patterns. According to this technique, a separate optical pattern is provided for each mold pin. The technique is disadvantageous because it requires the step of cutting the mold pins from the patterned substrate.
It has also been suggested to form a mold apparatus with a flat portion and a “stamper” opposed to the flat portion. Audio or video data may be digitally patterned in the stamper by lithography. The stamper is used to define disc-shaped molded products. This approach is disadvantageous because it produces only one product per injection mold cycle. Additional processing steps are required to form multiple products per mold cycle.